"You will fight the Arabian Peninsula and victory will be granted by Allah. Then you will fight the Romans and victory will be granted (by Allah). Then you will fight Dajjal and victory will be granted (by Allah)." Jabir said: "Dajjal will not appear until you have fought the Romans."
Sunan Ibn Majah Book 36, Hadith 167
← Previous Hadith “When the fierce battles take place, Allah will send a troop of freed slaves who will be the best Arab horsemen and the best armed, with whom Allah will support His religion.”

Sunan Ibn Majah Book 36, Hadith 166 Next Hadith → "The great fierce battle, the conquest of Constantinople and the emergence of Dajjal, will all happen within seven months."

Sunan Ibn Majah Book 36, Hadith 168